************************************** ARTICLES OF INTEREST ON ANTARCTICA ************************************** PROJECT EXPLORE INSTRUCTIONAL MODULE #2 FOCUS QUESTION: WHAT IS THE WEATHER AND CLIMATE OF ANTARCTICA? ............................................................................ Keith Randa Apple Valley High School Apple Valley, Minnesota BACKGROUND INFORMATION Antarctica is the southern-most continent on Earth. The South Pole is located on the continent of Antarctica. This pole represents the axis about which the Earth is rotating. Antarctica's location presents a unique situation in terms of weather and climate. We will begin the study of Antarctica's weather with a look at the causes of weather, climate, and seasonal change. CAUSES OF THE SEASONS ON EARTH: 1-The tilt of the Earth's Axis is 23 1/2 degrees from vertical. The North Pole is always pointed toward the star Polaris. The sun's rays that strike the Earth are parallel. 2-Rays from the sun range from direct to indirect. A-Direct rays strike the surface of the Earth at close to a 90 degree angle. Direct rays are more concentrated. This concentrated energy provides more heat. B-Indirect rays strike the surface at angles less than degrees. Indirect rays are more spread out. The spread out rays provide less heat. The sun's rays are parallel when they reach the Earth and the curvature of the Earth is what causes the rays to be direct or indirect. The parts of the Earth that receives direct rays are hotter those receiving indirect rays are cooler. Summer in the Northern Hemisphere is caused by the North Pole's tilt toward the sun. The tilt causes the Northern Hemisphere to receive the most direct rays and have longer days. These two factors cause the temperatures to be warmer. Due to the tilt, the North Pole and Arctic Circle receive 24 hours of daylight. Even when the North Pole has continual daylight, the sun's rays are very indirect due to the Earth's curvature, and allows very little heating. At the same time the Southern Hemisphere has continual darkness, which means that it also receives indirect rays but has short days. These factors cause the cooler conditions of the winter. During this time, the South Pole has 24 hours of darkness lasting about six months. During the winter, the North Pole is tilted away from the sun and receives 24 hours of darkness. The tilt has effects on both the Northern and Southern Hemisphere. The tilt causes the Northern Hemisphere to receive less direct rays, and experience more hours of darkness. The Southern Hemisphere receives more direct rays and more hours of light, so they are experiencing summer. Although the South Pole experiences 24 hours of daylight, it stays cool because the sun's rays are so indirect. During the spring and fall, the axis of the Earth is not tilted relative to the sun but is perpendicular to the sun's rays. This means that the equator is receiving the most direct rays from the sun and is experiencing the warmest temperatures. This results in equal hours of daylight and darkness over the entire planet and occurs on the spring and fall equinoxes in March and September. Different temperatures on the Earth's surface are responsible for causing the weather. The unequal heating of the Earth's surface causes air pressure differences which in turn causes the winds, which move the weather systems that form around the Earth. Weather includes temperature changes, air movements, evaporation, formation of clouds, and precipitation. The energy to make all of these things happen comes from the sun. The weather in Antarctica is characterized by high winds, blowing snow, and extremely cold, dry air. The following is a summary of the weather conditions typically found in Antarctica. TEMPERATURE The average temperature at the South Pole is -57 degrees F., while the average temperature on the west side of the Antarctic Peninsula is 24 degrees F. In the Antarctic summer the temperatures range from 32 degrees F. to 59 degrees F. on the coast, and 5 degrees F. to -41 degrees F. inland. Warmer temperatures are due to the longer days that occur during the summer months. The mid-winter temperatures range from -40 degrees F. to 31 degrees F. on the coast and -126 degrees F. to -21 degrees F. inland. Winter temperatures are influenced by the shortage of sunlight during the Antarctic winter. In fact, the coldest temperatures are usually during late August before the return of the sun. Other factors besides the indirectness of rays from the sun and differences in length of daylight cause Antarctica to be so cold. These include: -The snow cover reflects the sun's light instead of absorbing it. In snow free areas land surfaces heated by the sun radiate heat back to the lower atmosphere causing warmer conditions. -The extreme dryness of the air, due to the cold temperatures, causes any heat that is radiated back into the atmosphere to be lost instead of being absorbed by the water vapor in the atmosphere. -Antarctica has a higher elevation which causes cooler temperatures. -During the winter, the size of Antarctica doubles as the surrounding sea water freezes blocking heat from the warmer surrounding ocean water. The oceans typically act as a heat source because water takes a much longer time to change temperatures as compared to the land. All of these factors combine to making Antarctica one of the coldest places on the Earth. WIND Wind is the movement of air from areas of higher pressure to areas of lower pressure. These pressure differences are caused by differences in temperatures. Generally, colder temperatures develop higher pressure due to the cool air sinking towards the Earth's surface. Lower pressure is due to warm air rising from the surface of the Earth. The rotation of the Earth causes these winds to curve as they move from an area of higher pressure to an area of lower pressure. Over the South Pole cold dense air sinks towards the surface. This sinking air flows outward from the pole towards the coast causing nearly constant wind and average about 11 miles per hour about 64% of the time. Occasionally the cold, dry air moving away from the interior highlands is accelerated by gravity to speeds up to 150 mph. These winds are called "katabatic winds." Wind causes two special problems in Antarctica: wind chill factor and localized blizzards. Wind chill is the cooling factor caused by the combination of wind and temperature to produce conditions that would be much colder than the temperature alone and is the most debilitating factor of Antarctic expeditions. Localized blizzards are caused when the surface wind sweeps up any loose snow, even if the skies above are clear and no snow is falling. These conditions make travel and outdoor activities virtually impossible. PRECIPITATION The low temperatures in Antarctica allow the atmosphere to hold very little water. The atmosphere above Antarctica has about 1/10th of the water vapor concentration found in temperate latitudes. The water vapor present largely comes from the ice free regions of the southern oceans. The water vapor falls as precipitation mostly in the form of snow. Rainfall is almost unknown. Antarctica is known as the world's largest desert because it receives an average of 2" of snow per year in the interior. The coasts receive an average of 1-2 feet of snow caused by frequent storms during the winter season. CLIMATE OF ANTARCTICA Climate is defined as the average weather for a region over a period of time with the two main features being temperature and precipitation. The main factors influencing climate are latitude, altitude, prevailing winds, topography, distance from large bodies of water, and nearby ocean currents. There are two main climatic regions in Antarctica: the coastal regions and the interior. The coastal regions of Antarctica are milder for the following reasons: -The lower latitude provides more direct rays from the sun in the summer and also shorter periods of darkness in the winter. -The closeness to the ocean means that in the summer coasts receive more moisture in the form of precipitation, and also have warmer temperatures due to the water's heat storing capability. The interior of Antarctica has the harshest climate in the world, even harsher than the North Pole. This is due to the following conditions: -The interior receives the most indirect rays from the sun which makes it cooler. -For long periods in the winter it receives no sunlight at all • The interior has a very high altitude which adds to the very cold temperatures. -Because the interior of Antarctica is a land mass and far away from the ocean, it gets no warming effect from the water. Overall, the coast is relatively warm and moist compared to the dry and cold interior. However, in comparison to other climates around the world, Antarctica is a very harsh place. OBJECTIVES: PROCESS OBJECTIVES 1-The student will be able to describe the weather that occurs in Antarctica. 2-The student will be able to describe the climates of Antarctica and compare the climates of Antarctica with the climate in which they live. CONTENT OBJECTIVES 1-The student will know where Antarctica is located. 2-The student will know how the angle of the sun's rays affects the heat received on Earth. 3-The student will know the factors which control the heating of the Earth's surface. 4-The student will understand the position of the Earth during the different seasons for both the Northern and Southern Hemispheres. 5-The student will understand why the poles experience 24 hours of daylight or 24 hours of darkness during the year. 6-The student will define weather. 7-The student will know what factors contribute to the cold temperatures in Antarctica. 8-The student will understand the conditions which cause wind. 9-The student will understand how the wind makes outdoor activities difficult in Antarctica. 10-The student will understand why Antarctica receives so little precipitation each year. 11-The student will define climate. 12-The student will understand the factors which control the climate of Antarctica. EQUIPMENT AND MATERIALS Team Bulletins from LEARNING LINK, Paper, pencil, Graph paper, Color pencils, Construction paper, Rulers, library resources. EXPLORATION/PRIOR KNOWLEDGE ASSESSMENT This is an activity designed to stimulate student interest in the topic and provide an indication of students' prior knowledge of the topic. The information is important for determining the starting point and the level of difficulty for instruction. Have the students answer the following questions: 1-Describe what the weather is like at the South Pole (Antarctica). Include such things as temperature, wind, rain, or snow. 2-List the clothing that you would take to Antarctica including amounts of each (i.e., 2 pairs of socks). 3-Explain why Antarctica is colder or warmer than where you live. 4-Describe in 3 or 4 sentences the difference between climate and weather. 5-Describe what you think is the perfect climate for yourself and what activities you would like to do in that climate. CONCEPT INVENTION ACTIVITY Here are a few suggested ways to present the background materials for this module: 1-If you have access to audiovisual materials about Antarctica, and its weather and climate, show the materials to the class. 2-Give a lecture and a set of notes on the weather and climate of Antarctica. 3-Have the students read the background information and answer the questions on the Antarctica Weather and Climate Worksheet. 4-Have the students do research in the library about the weather in Antarctica. ANTARCTICA WEATHER AND CLIMATE WORKSHEET NAME: PER.: 1-What is the driving force for weather on the Earth? 2-Explain why direct rays produce more heat than indirect rays? 3-What is weather? 4-List some factors which cause Antarctica to be so cold. 5-Why is there so little precipitation in Antarctica? 6-Fill in the following table of weather conditions. Location - Temp. Range - Wind - Amount of Snow/year Antarctic Coast Antarctic Interior 7-What is climate? What are the two main features of climate? 8-What factors influence the climate of Antarctica? 9. Which of the two Antarctic climates would you choose to live in? Explain what conditions there are that would want you to live there. Explain what kind of outdoor activities you could do in that climate. APPLICATION ACTIVITIES Select one or more of the following activities to provide students with practice applying their new knowledge. 1-Weather of the Expedition In this activity, students will look at the weather that the expedition will encounter as they travel across Antarctica. They will also evaluate what types of weather might interfere with the activities of the expedition. 2-Climate comparison activity In this activity, students will plot temperature and precipitation graphs for three different locations. They will then determine the factors which are responsible for these climates. They can then pick the perfect climate and what they would do for employment and recreation in that environment. They will then compare their perfect climate with Antarctica's climate. 3-Antarctica Travel Brochure Working in groups of two, students will design a travel brochure that could be given to travelers to Antarctica. Included in the brochure would be information about the seasonal weather along with suggested attire and a list of possible activities designed to entice a traveler to make a trip to Antarctica. APPLICATION ACTIVITY #1: WEATHER OF THE EXPEDITION PURPOSE: To have students see what type of weather the Expedition is encountering and to see what affects the weather has on the activities and progress of the Expedition. BACKGROUND: The team members of the Trans-Antarctica Expedition are encountering some of the harshest weather known on the Earth. The very cold temperatures, strong winds, and blowing snow make outdoor activities very difficult. The weather is a major factor determining whether or not the trek can be finished. PROCEDURE: 1-Each team (2 people) should select one week of the Expedition to work with. 2-Using the team bulletins from LEARNING LINK, each team should fill out the data table for their week of the Expedition. 3-After the table is finished, the team should write a summary of the week. The Summary should include the following: -Temperature range for the week -Average temperature of the week. -Range of wind speed for the week. -Average wind speed of the week. -Other weather conditions encountered during the week. -Distance covered during the week. -Any other difficulties caused by weather during the week. -Overall statement explaining how the weather affected the team's progress or activities. 4-Team members should share their summary with others in one of the following ways. -Meet in small groups of 8-10 to share summaries. -Share the summaries orally in front of the whole class. 5-The class may get together to discuss the following: -What are the general weather conditions encountered by the team traveling across Antarctica? -Did the weather improve as they got further along in their trip? -How does the weather that they are encountering compare with the weather that we are encountering during the same time? -How do you think you could manage to survive in the weather of Antarctica? A Week of Antarctica Weather Table Day 1 Day 2 Day 3 Day 4 Day 5 Day 6 Day 7 Date Temp. Precip. Wind. Special Weather Conditions Mileage Other Problems APPLICATION ACTIVITY #2: ANTARCTICA CLIMATE COMPARISON PURPOSE: To compare the climate of Minneapolis, MN; Yuma, AZ; Honolulu, Hawaii; South Pole Station, Antarctica; Wilkes, Antarctica; To see what factors influence the climate of each location. To make some lifestyle decisions about each climate. BACKGROUND: Climate is the average weather over a region for a period of time. The two main features of climate are temperature and precipitation. There are several factors which work together to influence the climate. These factors are latitude, altitude, prevailing winds, topography, proximity to oceans, and ocean currents. The climate of Antarctica is vastly different from the climate of the rest of the Earth. It is influenced strongly by its location on the Earth, it's altitude and the fact that the Earth is tilted in its orbit around the sun. In this activity, we will look at the climates of five locations and determine what factors influence each climate. PROCEDURE: 1-Set up a graph like the one shown below for each of the five locations given in the climate data table. | | | | | | Temperature | | Precipitation | | | | | | |_____________________| J F M A M J J A S O N D 2-Plot the climate data for the five locations on each of the five graphs. CLIMATE DATA: Temperature in degrees Fahrenheit = T Precipitation in inches = P Month Loc. #1 Loc. #2 Loc. #3 Loc. #4 Loc. #5 T P T P T P T P T P Jan. 13 0.7 72 3.7 55 0.4 -20 0.1 31 0.5 Feb. 16 0.8 72 3.3 59 0.4 -38 0.1 25 0.4 March 27 1.5 73 2.9 66 0.2 -55 0 19 1.7 April 46 1.9 74 1.3 70 0.1 -73 0 13 1.1 May 57 3.2 76 1.0 79 0 -73 0 10 1.4 June 66 4.0 78 0.3 88 0 -74 0 7 1.2 July 72 3.3 79 0.4 91 0.1 -74 0 5 1.3 Aug. 70 3.2 79 0.9 93 0.5 -69 0 7 0.8 Sept. 61 2.4 79 1.0 93 0.5 -65 0 9 1.5 Oct. 49 1.6 78 1.8 72 0.2 -60 0.1 11 1.2 Nov. 32 1.4 76 2.2 64 0.1 -48 0 18 0.8 Dec. 21 0.9 74 3.0 57 0.3 -34 0.1 24 0.3 3- After you have finished all five graphs, determine which city each graph represents and label each graph with the name of the appropriate city. Your choices are: -Minneapolis, MN -Yuma, AZ -Honolulu,Hawaii -South Pole Station, Antarctica -Wilkes, Antarctica SUMMARY QUESTIONS: INTERPRETING YOUR GRAPHS: 1-Label each graph with it's location if you have not done so. Explain your reasons for deciding which location goes with each graph. LOCATION REASONS Minneapolis, MN Yuma, AZ Honolulu, Hawaii South Pole Station, Antarctica Wilkes, Antarctica 2-Remember that climate is the average weather over a period of time. How would you describe the climate in: Minneapolis, MN Yuma, AZ Honolulu, Hawaii South Pole Station, Antarctica Wilkes, Antarctica 3-Which graph shows the greatest temperature range? -What factor would explain this? 4-Which graph shows the smallest temperature range? -What factor would explain this? 5-What are the differences in climate between the two Antarctica locations? 6-Explain the difference in climate between the two Antarctica locations? LIFESTYLE QUESTIONS: 1-Fill out the following chart with activities that people enjoy doing in each location during the summer and winter. Location Summer Winter Minneapolis Yuma Honolulu South Pole Station Wilkes 2-What are some "SIMPLY MUST HAVE ITEMS" items of clothing for a complete wardrobe in: Minneapolis: Yuma: Honolulu: South Pole Station: Wilkes: 3-Which of the locations that we looked at in this activity would you prefer to live in? Explain why? 4-Which of the locations that we looked at in this activity would you prefer to go to on vacation? Explain why? 5-Which of the locations that we looked at in this activity would you never want to visit? Explain why? 6-****** BONUS QUESTION ******* HOW ARE HOMES AND BUILDINGS DESIGNED DIFFERENTLY IN THESE LOCATIONS IN ORDER TO DEAL WITH CLIMATE? APPLICATION ACTIVITY #3: ANTARCTICA TRAVEL BROCHURE PURPOSE: To investigate the weather and climate of Antarctica by designing a travel brochure. The brochure should contain information about the weather to expect, what types of clothing tourists need, and activities they can do in Antarctica. BACKGROUND: Antarctica has weather that is much different than most places in the world. Even though the weather is very cold and harsh throughout most of the year, tourists travel to Antarctica each year. In this activity you will inform potential tourists about what to expect when they travel to Antarctica. PROCEDURE: You are to design a brochure that will inform people about what they might experience in Antarctica and explain why they should travel there. Your brochure will be designed on an 8 1/2" x 11" piece of paper. Your brochure should include the following: -Average weather expected in Antarctica each season. -Activities that people could do in Antarctica. -Drawings showing where Antarctica is located. -Drawing or pictures showing what people can see in Antarctica. -Clothing that people should bring to wear in Antarctica. -Anything else that you feel would be important to add. Your completed brochure is due on (DATE). EVALUATION: ANTARCTICA WEATHER TEST MULTIPLE CHOICE QUESTIONS 1-Antarctica summer temperature range would be: a. 10 degrees C. to 90 degrees C. b. -20 degrees C. to -30 degrees C. c. -10 degrees C. to -75 degrees C. d. -50 degrees C. to 10 degrees C. 2-If the Earth was not tilted on it's axis: a. There would not be any seasons. b. One half of the Earth would always have daylight c. The whole Earth would be colder d. The whole Earth would be warmer 3-This location experiences a 6 month day and 6 month night each year: a. Antarctic circle b. Arctic circle c. North geographic Pole d. South geographic Pole 4-During which season is there 24 hours of daylight in Antarctica? a. Summer b. Winter c. Fall d. Spring 5-During which season is there 24 hours of night in Antarctica? a. Summer b. Winter c. Fall d. Spring TRUE/FALSE QUESTIONS: 1-Antarctica is warmer than the Arctic. 2-The interior of Antarctica receives over 8 feet of snow each year. 3-Wind chill has no effect on travelers in Antarctica. 4-The ice in Antarctica doubles in size during the winter. 5-Blizzards in Antarctica occur only while snow is falling. ESSAY/SHORT ANSWER QUESTIONS: 1-List and explain the factors which cause the Earth's seasons. 2-Explain why direct rays are warmer than indirect rays. 3-In the space below draw a sun in the middle and four Earths around the sun. Show the tilt of the Earth towards the right side of the paper. For each Earth do the following: -Label the season that each Earth is on. -Label the date when the Earth will be in that position. -Label the season for the Northern and Southern Hemisphere for each position. 4-What factors cause Antarctica to be so cold? 5-What causes the wind to blow? 6-What are two special conditions caused by the wind in Antarctica? 7-How is the climate of Antarctica different from where you live?